MishaT's well-known Nautilus Gears, re-drawn for laser cutting rather than printing, and with a simple motorised display stand.
Plain laser cutting, although you will need clean cuts as the septa in the nautilus are quite thin.
For basic gears, just cut the left hand gear from page #1. Page #2 is a simple display stand for them, using bamboo barbecue skewers as axles.
Motorised display is on #3. This is a stand for one of the cheap and common geared motors. I used 200:1 reduction, but the 120:1 are maybe a bit quieter. It would be nice to add PIR sensor triggering too.
Use one of the right-hand nautilus gears to fit the motor shaft
The stand is straightforward laser-cut mortice and tenon joinery, but slightly tapered. It's drawn to cut from 3mm MDF. The front panel also has a useful and re-usable layout for mounting these motors.
There are two front panels, the slightly larger one is a false front to cover the screw heads and the wood joints. As I didn't have any countersunk screws (M3 x 25) handy, I cut a couple of ugly holes in here at the last moment to give screw head clearance. If you countersink the screws into the inner panel, you could avoid this!
Small 2×AA battery box inside, just wedged into place against the motor. The oval hole in the back panel accesses the switch.
Once you've made the inner stand, wrap the living hinge outer wrapper around it and clamp into place while the glue sets. This uses the hinge pattern from MSRaynsford's ring box, slightly stretched onto the taper.
Be careful pressing the gear onto the motor, it's a tight fit and they're fragile!
Corel Draw and PDF formats. Mostly just cut the black lines and ignore the red lines, as they're only construction lines.